917
FXUS21 KWNC 141830
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT MAY 14 2026
SYNOPSIS: MID-LEVEL LOW PRESSURE UNDERCUTTING MID-LEVEL HIGH PRESSURE OVER THE
EASTERN PACIFIC IS ANTICIPATED TO BUILD INTO PARTS OF THE WESTERN CONTIGUOUS
U.S. (CONUS) AT THE START OF WEEK-2. THIS REDUCES CHANCES FOR EXTREME HEAT
ACROSS THE CALIFORNIA CENTRAL VALLEY. THERE ARE SOME LINGERING CHANCES FOR HIGH
WINDS ALONG PARTS OF THE WEST COAST EARLY IN WEEK-2, AS THE MID-LEVEL LOW
PRESSURE MOVES INTO THE REGION. MEANWHILE, SOUTHERLY RETURN FLOW INTO THE
SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY INCREASES CHANCES FOR HEAVY
PRECIPITATION.
HAZARDS
SLIGHT RISK OF HEAVY PRECIPITATION FOR PORTIONS OF THE SOUTHERN PLAINS AND
LOWER MISSISSIPPI VALLEY, FRI-MON, MAY 22-25.
SLIGHT RISK OF HIGH WINDS FOR PORTIONS OF THE OREGON AND CALIFORNIA COAST, FRI,
MAY 22.
DETAILED SUMMARY
FOR SUNDAY MAY 17 - THURSDAY MAY 21:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR FRIDAY MAY 22 - THURSDAY MAY 28: ACROSS NORTH AMERICA, ENSEMBLE GUIDANCE
FROM THE 0Z RUNS CONTINUES TO EXHIBIT SIGNIFICANT SPREAD THROUGHOUT THE WEEK-2
TIMEFRAME. WHILE POSITIVE 500-HPA HEIGHT ANOMALIES ARE FAVORED FOR MUCH OF THE
EASTERN CONUS, SLIGHT DISCREPANCIES PERSIST BETWEEN THE GEFS, ECENS, AND CMCE
CONCERNING THE PRECISE CORE OF THIS MID-LEVEL FEATURE; CURRENT INDICATIONS
PLACE THE MEAN CENTER OVER THE GREAT LAKES. CONVERSELY, NEGATIVE 500-HPA HEIGHT
ANOMALIES ARE FAVORED ACROSS THE WEST, UNDERCUTTING A MID-LEVEL RIDGE OVER THE
EASTERN PACIFIC.
SURFACE HIGH PRESSURE IS ANTICIPATED TO DEVELOP UNDERNEATH THE MID-LEVEL RIDGE
SITUATED OVER THE EASTERN U.S., POTENTIALLY INITIATING A PHASE OF INCREASED
SOUTHERLY RETURN FLOW INTO THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY.
WHILE MEAN ENSEMBLE GUIDANCE DOES NOT CURRENTLY INDICATE A ROBUST FLOW,
DISCRETE ENSEMBLE MEMBERS SUGGEST THE POSSIBILITY OF STRONGER MOISTURE FLOW
INTO THIS AREA. UNCALIBRATED GEFS AND ECENS FORECASTS DENOTE 30-50%
PROBABILITIES OF THREE-DAY RAINFALL TOTALS SURPASSING ONE INCH DURING THE 8-10
AND 10-12 DAY WINDOWS. THIS IS CORROBORATED BY THE PROBABILISTIC EXTREMES TOOLS
(PETS), WITH BOTH THE GEFS AND ECENS PETS SHOWING AT LEAST A 20% CHANCE OF
EXCEEDING THESE THRESHOLDS; THE ECENS IS NOTABLY STRONGER, SUGGESTING 30-50%
CHANCES DURING BOTH PERIODS. GIVEN THE PREVAILING DROUGHT CONDITIONS, THESE
RAINS MAY PROVE BENEFICIAL. HOWEVER, ISOLATED FLASH AND URBAN FLOODING IS
POSSIBLE AND RIVER RISES ARE ALSO POSSIBLE IN PARTS OF EASTERN TEXAS.
CONSEQUENTLY, A SLIGHT RISK OF HEAVY PRECIPITATION IS VALID FOR MAY 22-25
ACROSS PORTIONS OF THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY.
A SLIGHT RISK OF HIGH WINDS IS VALID FOR MAY 22 ACROSS PORTIONS OF THE OREGON
AND CALIFORNIA COAST. CURRENT ENSEMBLE GUIDANCE INDICATES CYCLONIC MID-LEVEL
FLOW POSITIONED SOUTH OF AN ANOMALOUS RIDGE OVER THE NORTHEASTERN PACIFIC,
WHILE SURFACE GUIDANCE SUGGESTS PERIODS OF INTENSIFYING PRESSURE GRADIENTS
THROUGHOUT THE REGION.
THE ECENS UNCALIBRATED AND PETS GUIDANCE HAS BEEN QUITE CONSISTENT IN BRINGING
A 20-40% CHANCE OF 1 INCH OF PRECIPITATION TO PORTIONS OF THE CAROLINAS AND
MID-ATLANTIC ASSOCIATED WITH A WEAK AREA OF LOW PRESSURE. THE GEFS HAS NOT BEEN
AS SUPPORTIVE OF THIS POTENTIAL BUT CONTINUES TO BRING SOME CHANCES INTO
PORTIONS OF THE CAROLINAS. NO ASSOCIATED HAZARD IS POSTED TODAY BUT DOES BEAR
WATCHING FOR THE MEMORIAL DAY WEEKEND. FURTHER NORTH, SURFACE HIGH PRESSURE MAY
BRING ENHANCED ONSHORE FLOW INTO PORTIONS OF THE NORTHERN MID-ATLANTIC
ELEVATING SURF ALONG THE COAST.
IN ALASKA, THE TYPICAL PEAK OF THE RIVER ICE BREAKUP SEASON IS APPROACHING, AND
ICE JAM FLOODING CAN OCCUR THIS TIME OF YEAR WITH LITTLE OR NO NOTICE AS
CONDITIONS ON FROZEN RIVERS CAN CHANGE QUICKLY. PLEASE CHECK WITH THE ALASKA
PACIFIC RIVER FORECAST CENTER FOR THE LATEST CONDITIONS AND ADVISORIES.
FORECASTER: RYAN BOLT
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